For a liquid crystal display (LCD) panel driven by a thin film transistor-liquid crystal display (TFT-LCD), a circuit hoard driving a scan line may be omitted in order to save cost. Thus, a signal driving a gate electrode is sent to the scan line via cabling arranged in an inner part of the LCD panel. As shown in FIG. 1 and FIG. 2, an input voltage of a gate driver chip is generated by a driving chip (power integrated circuit card, power IC) of a control board, and is transmitted to a gate driver (GD) via a circuit board of a source driver (as shown X Board in FIG. 1), which needs the cabling to be arranged in the inner part of the LCD panel (wire on array: WOA). A resistance exists in the cabling, because the cabling is limited, by a layout and production process of the LCD panel, thus a voltage difference is generated in the cabling when current flows through the cabling. As shown in FIG. 3, STV represents a frame synchronizing signal. One cycle represents one frame. VGL_P represents a control voltage (VGL) generated in the control hoard, and VGL_C represents a voltage when the VGL reached the GD1 or GD3 on the LCD panel. The VGL_C is high on an upper half of one frame, where an obvious voltage difference is formed.
When the voltage difference is great, namely that the VGL voltage difference acting on two gate driver chips is greater, it leads to a color difference be displayed on the pictures of upper half and lower half of the LCD panel. An obvious horizontal dividing line is seen in a middle of the picture, which affects display quality.